www.springer.com/journal/13296 International Journal of Steel Structures September 2012, Vol 12, No 3, 427-442 DOI 10.1007/s13296-2012-3011-9 Inelastic Local Buckling of Curved Plates with or without Thickness-tapered Sections Using Finite Strip Method Sh. Kasaeian 1 , M. Azhari 1 , A. Heidarpour 2, *, and A. Hajiannia 1 1 Department of Civil Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran 2 Department of Civil Engineering, Building 60, Monash University, Melbourne, VIC 3800, Australia Abstract This paper addresses the inelastic local buckling of the curved plates using finite strip method in which buckling modes and displacements of the curved plate are calculated using sinusoidal shape functions in the longitudinal direction and polynomial functions in the transverse direction. A virtual work formulation is employed to establish the stiffness and stability matrices of the curved plate whilst the governing equations are then solved using a matrix eigenvalue problem. The accuracy and efficiency of the proposed finite strip model is verified with finite element model using ABAQUS as well as the results reported elsewhere while a good agreement is achieved. In order to illustrate the proposed model, a comprehensive parametric study is performed on the steel and aluminium curved plates in which the effects of curvature, the length of the curved plate as well as circumferential boundary conditions on the critical buckling stress are investigated. The developed finite strip method is also used to determine the buckling loads of the curved plates with thickness-tapered sections as well as critical stresses of the aluminium cylindrical sectors that are subjected to uniform longitudinal stresses. Keywords: finite strip method, inelastic, local buckling, curved plate, thickness-tapered sections 1. Introduction Cylindrically curved panels are efficient structures with wide applications in aircrafts, submarines, cooling towers, jet nozzles, and petrochemical and construction industries. A strong engineering aspiration is to reduce the weight of such panels for their improved performance particularly in aerospace applications. However, the quest to design lightweight structures often allows local buckling to occur at design load levels where the axial compression is the major primary action in curved plates, and therefore when thin-curved plate structures are subjected to compressive loads their behaviour may be governed by buckling. The buckling behaviour of the curved plates has been investigated by a few researchers during recent years. Dawe (1977) was presented a finite strip method for calculating the linear buckling stresses of structural assemblies of thin curved plates that were rigidly joined together at their longitudinal edges and were simply supported at circumferential ends. It was assumed that the displacements varied sinusoidally in the longitudinal direction while high-order polynomial variations of the displacement components around the plate width were taken into consideration. A parametric study of the nonlinear behaviour of curved plates under circumferential compression was undertaken by Jacques et al. (1983). The influence of the geometrical parameters, curvature and slenderness was investigated using finite element model while general design formula for curved plates was proposed for specific ranges of curvature and slenderness. Vibration and buckling of hybrid laminated curved panels was investigated by Barai and Durvasula (1992) using first- order shear deformation theory and Reissner’s shallow shell theory in which only simply supported boundary conditions were considered. Using the energy method the natural frequencies and critical buckling loads were calculated while a combination of sine and cosine functions in the form of double Fourier series was assumed. It was concluded that the non-dimensional frequencies and critical buckling load of a hybrid laminate lie in between the values for laminates made of all plies of higher strength and lower strength fibres whilst curvature might enhance natural frequencies. Rayleigh-Ritz method was employed by Wang et al. (1994) to investigate the vibration and buckling of supper elliptical plates that are used in curved corners to diffuse stress concentration. It Note.-Discussion open until February 1, 2013. This manuscript for this paper was submitted for review and possible publication on Sep- tember 8, 2011; approved on September 6, 2012. © KSSC and Springer 2012 *Corresponding author Tel: +61-3-99024435; Fax: +61-3-99054944 E-mail: amin.heidarpour@monash.edu